<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    [class*="test-"] {
      width: 200px;
      height: 200px;
      background-color: red;
    }
  </style>
</head>
<body>
<div class="aa test-b"></div>
</body>
</html>